Final answer:
Epinephrine and norepinephrine are released by the adrenal glands, specifically the adrenal medulla, and are critical in the body's fight-or-flight response to stress. Option a is correct.
Step-by-step explanation:
Epinephrine and norepinephrine are fight-or-flight hormones that are crucial for the body's response to stress. They are released by the adrenal glands, specifically the adrenal medulla.
These hormones have effects such as increasing the heart rate, increasing blood pressure, and redirecting blood flow to important organs like the muscles and the heart by constricting the blood vessels. The correct answer is a. adrenal glands.